github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/engine/pkg/adapter/keyadapter.go (about)

     1  // Copyright 2022 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package adapter
    15  
    16  import (
    17  	"encoding/hex"
    18  	"path"
    19  	"strings"
    20  
    21  	"github.com/pingcap/tiflow/pkg/errors"
    22  )
    23  
    24  // Defines all key adapters
    25  var (
    26  	DMJobKeyAdapter            KeyAdapter = keyHexEncoderDecoder("/data-flow/dm/job")
    27  	DMInfoKeyAdapter           KeyAdapter = keyHexEncoderDecoder("/data-flow/dm/info")
    28  	DMUnitStateAdapter         KeyAdapter = keyHexEncoderDecoder("/data-flow/dm/unit-state")
    29  	DMDroppedColumnsKeyAdapter KeyAdapter = keyHexEncoderDecoder("/data-flow/dm/dropped-columns/")
    30  )
    31  
    32  // KeyAdapter is used to construct etcd like key
    33  type KeyAdapter interface {
    34  	Encode(keys ...string) string
    35  	Decode(key string) ([]string, error)
    36  	Path() string
    37  	Curry(keys ...string) KeyAdapter
    38  }
    39  
    40  type keyHexEncoderDecoder string
    41  
    42  func (s keyHexEncoderDecoder) Encode(keys ...string) string {
    43  	hexKeys := []string{string(s)}
    44  	for _, key := range keys {
    45  		hexKeys = append(hexKeys, hex.EncodeToString([]byte(key)))
    46  	}
    47  	ret := path.Join(hexKeys...)
    48  	//if len(keys) < keyAdapterKeysLen(s) {
    49  	//	ret += "/"
    50  	//}
    51  	return ret
    52  }
    53  
    54  func (s keyHexEncoderDecoder) Decode(key string) ([]string, error) {
    55  	if key[len(key)-1] == '/' {
    56  		key = key[:len(key)-1]
    57  	}
    58  	v := strings.Split(strings.TrimPrefix(key, string(s)), "/")
    59  	//if l := keyAdapterKeysLen(s); l != len(v) {
    60  	//	return nil, terror.ErrDecodeEtcdKeyFail.Generate(fmt.Sprintf("decoder is %s, the key is %s", string(s), key))
    61  	//}
    62  	for i, k := range v {
    63  		dec, err := hex.DecodeString(k)
    64  		if err != nil {
    65  			return nil, errors.WrapError(errors.ErrDecodeEtcdKeyFail, err, k)
    66  		}
    67  		v[i] = string(dec)
    68  	}
    69  	return v, nil
    70  }
    71  
    72  func (s keyHexEncoderDecoder) Path() string {
    73  	return string(s)
    74  }
    75  
    76  func (s keyHexEncoderDecoder) Curry(keys ...string) KeyAdapter {
    77  	prefix := s.Encode(keys...)
    78  	if prefix[len(prefix)-1] != '/' {
    79  		prefix += "/"
    80  	}
    81  	return keyHexEncoderDecoder(prefix)
    82  }